选择性激光烧结塑料功能件工艺及材料的研究

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1、华中科技大学硕士学位论文选择性激光烧结塑料功能件工艺及材料的研究姓名：吴传保申请学位级别：硕士专业：高分子化学与物理指导教师：刘承美2003.5.13华中科技大学硕士学位论文AbstractSLS(SelectiveLaserSintering)partusedinperformancetestisnamedfunctionalpart(FP)．itneedsgivenmechanicalstrengthanddimensionalaccuracy．PSCan’tbeusedtomakeFPdirectlybecauseo

2、fthepoors订engthofPSpartmadefrompurePS．Nyloncan’tbeusedtomakeFPbecausewarpandmovementduringsintering．Inordertoimprovethepart’Sperformance，threesidesofworkshouldbedoneonsinteringtechnology,powder’Spropertiesandmaterial’Sintrinsicperformancewhichaffectpart’sperforman

3、ce．Differentmaterialshavedifferentwarp．Whenthelaserpowerchangefrom12．5wattto22．5watt．thewarpofnylon12firstlyincreasesandthendecreases．WhentheSCanspaceincreasesfromO．01mmtoO．05mm．thewarpheightofnylon12increasesandreaches7．8mmat0．05mmscanspace．Whenthelaserpowerincre

4、asesfrom17．5wattto27．5watt．thewarpofPS(polystyrene)decreasesfrom3．3mmto1．5rrtm．EVA(ethylene—vinylacetatecopolymer)doesn’twarpduringsintering．Theshrinkageofnylon12，PSandEVAincreasesasthelaserpowerincreases．Theseindicatethattherearenotsimplecorrespondingrelationship

5、betweenwarpandshrinkage．ThemovementdistanceofPSpiecedecreasesfrom6．3to2．8mmwhenthethicknessoflayerincreasesfromO．05ramtoO．6mmbecausereducedlayerthicknessincreasespowder’Ssheartopart．Thediameteranddistribution，shape，blockingofpowderinfluencethepowder’Sflowandappare

6、ntdensity．TheblockingofpolytetrafluomethylenepowderandCOarsesurfaceofpolycarbonatepowdermaketheirflowabilitylowerthanPSpowder．Theflowabilitydecreasesasthediameterofpowderdecreases．AfterPSpowderwasfilledwithactivatedCaC03，thewarp，movementandshrinkagereducedobviousl

7、yandtheflowabilityofpowderdecreases．Aftersurfacesulfonation，PSpowder’shydrophilicityisimprovedanditCandisperseinwatereasilyandstably．AfterthesulfonatedpolymerWasneutralized，powderdoesn’tchangeit’Scolorinvacuulrlat100*Cfor12h．Itdisplayedthatafterneutralizationsulfo

8、natedPSpossessedhigIlthermalstability．ThesulfonationabilityofconcentratedH2S04ishigherthanthatofsulfuricacetatewhencyclohexaneusedassolvent，buttheirsulf